Apparatus and process for heating fluids



J. cs. ALTH ER 2,081,970

APPARATUS AND PROCESS FOR. HEATING FLUIDS 3 Sheets-Sheet 1 June 1 1937.

Original Filed July 23, 1930 9 LRNAC-E BURN INVENTOR JOSEPH G. ALTHERATTORNEY I June 1, 1937. J. G. ALTHER 2,031,970

' APPARATUS AND PROCESS FOR HEATING FLUIDS ori inal Fiied July 25. 1950s Sheets-Sheet 2 INVENTOR JOSEPH G. ALTHER ATTORNEY June 1, 1937. J. G.ALTHER 8 APPARATUS AND PROCESS FOR HEATING FLUIDS Original Filed July25, 1930 3 Sheets-Sheet 3 FIG. 8

INVENTOR JOSEPH G. ALTHER macaw-awn Patented June 1, 1937 UNITED STATES363")" nuu PATENT OFFICE Joseph G. Alther, Chicago, Ill., assignor, bymesne assignments, to Universal Oil Products Company, Chicago, 111., acorporation of Delaware Application July 23, 1930, Serial No. 470,088Renewed August '7, 1935 4 Claims.

This invention relates to an apparatus and process for heating fluids,and more particularly the invention provides a means and process whereinthe fuel may be utilized in the most efficient manner and the heat maybe transferred to the fluids being heated in a controlled and efficientmanner with respect to the heat transfer and fuel efficiency and thekind or type of heat.

The invention further provides a process wherein part of the tubesurface is heated substantially by radiant heat from the flame, gasesand reflecting and radiating surfaces of the furnace structure, and theother part thereof is heated substantially by fluid heat consisting ofconvection heat with some radiant heat from the gases.

In carrying out the objects of the invention, the heating tubes areprovided with fins adhering or made integral thereto, the said finsoverlapping each other in such manner as to constitute a Wall or barrierenclosing a chamber or compartment wherein combustion takes place andwherein the heat transferred to the tubes is substantially of theradiant type. The hot gases of combustion passover the top of the wallsenclosing the combustion chamber and pass down over the outer surface ofthe walls surrounding the combustion chamber (the said walls, asdescribed, being composed of the overlapping fins adhering to thetubes), in a separate compartment surrounding the combustion chamber,and in turn being surrounded by the walls of the furnace proper. Thegases passing through the outer compartment heat the exposed tubesurfaces thereof by substantially fluid or convection 35 heat.

It is thus apparent that my invention provides a novel means and processfor the heat treatment of fluids wherein one side of the heating tubesis heated substantially by radiant heat and the other side is heatedsubstantially by fluid heat. This is a novel feature in furnacesemploying finned tubes, as tubes of this character are generallyutilized to shield the roof and walls of the furnace (particularly inthe radiant heat section) and as so used are effective for heating onlyon their inner or exposed side.

Other advantages and desirable features of my invention will be moreapparent by reference to the accompanying drawings, which arediagrammatic and are not to scale, and which illustrate a form ofapparatus-suitable for carrying out the process of my invention withexamples of arrangements of the means therefor.

Fig. 1 is a side elevational View, partly in cross 55 section, of acircular furnace assembly.

Figs. 2, 3, 4, 5 and 6 are plan views of typical furnace shapesillustrating some of the many forms and shapes which may be utilized.

Figs. '7, 8 and 9 show several difierent types of tube fin structuresand the manner in which they overlap.

Referring to Fig. 1, l represents a burner which may be of anyconventional type for oil, gas or other fuel, such as powdered coal. 2is a firing compartment with brick checker work arrangement. It is to beunderstood that any firing arrangement may be used. 3 is the combustionchamber. Radiant heat is transferred from the hot brick checker work ofthe firing compartment and from the flames and gases in the combustionchamber 3 to that portion of the surfaces of the tubes exposed withinthe combustion chamber. 4 represents the walls composed of theoverlapping tube fins, and 5 represents the heating tubes connected inseries. The tubes may be arranged so that several sets or banks ofserially arranged tubes may be connected in parallel.

The furnace is designated as a whole 1. the walls 8 being made up, ifdesired, of an integral course of rows of bricks or of parallel courseswith an air space between the same, the outer course usually being madeup of common brick and the inner course of firebrick.

Suitable steel structural work (not shown) may be used to support thewalls 8 and roof 9. The tubes are supported at the top by tube supportl0, and at the bottom by the floor ll of the furnace.

The hot gases leaving the combustion chamber 3 pass over the top of thewall of fins 4 into the fluid heating compartment l2. The hot gasespassing downwardly through this compartment transfer fluid or convectionheat to the portions of the tubes exposed in this compartment, the gasesultimately passing out through the circular flue l3 at the bottom of thefurnace, and from there through the duct l4 to the stack.

Figs. 2, 3, 4, 5 and 6 illustrate various shapes and forms of a crosssection of the furnace taken on line A-A in Fig. 1. The tubes 5connected by fins 4 areshown parallel to the outer walls of the furnacein the figures. Fig. 2 represents a circular arrangement. Fig. 3 is asquare. Fig. 4 is a pentagonal, Fig. 5 a hexagonal, and Fig. 6 anoctagonal arrangement. These figures illustrate only a few of the manyforms which the furnace may assume.

Figs. '7, 8 and 9 represent cross sections of the tubes 5 with theadhering fins 4, showing the manner in which the fins may overlap andillus- CJI trating only several of the many forms which may be used.

While my invention may be adapted to the heating of any fluid, it isparticularly adapted to the heating of hydrocarbon oils, and in one ofits specific embodiments provides an improved process 'for theconversion of higher boiling hydrocarbon oils into lower boilinghydrocarbon oils.

Fig. 1 is illustrative of the heating means of a process suitable forthe conversion of higher boiling hydrocarbon oils into lower boilinghydrocarbon oils, wherein the oil is heated to its conversiontemperature and the vapors and unvaporized liquid thereafter separatedfor further treatment.

My invention also finds use as an efiicient heating means for theproduction of steam and is useful wherever it is desirable to heatfluids in a thoroughly eflicient manner.

While I have shown several forms of apparatus and their application incarrying out the process of my invention, it is quite apparent thatthere are many variations thereof, and the forms shown are not to beconstrued as limitations upo the broad scope of the invention.

I claim as my invention:

1. A furnace for heating hydrocarbon oil, comprising a housing, acombustion zone therein, a heat source disposed within said combustionzone, an outlet flue and a convection zone in communication with saidcombustion zone, a plurality of serially connected tubes disposedintermediate said combustion zone and said convection zone, and finsprojecting from saidtubes adapted to form a substantially continuouswalled partition between said zones, whereby the opposite surfaces ofsaid tubes are subjected to separate and simultaneous heating by radiantand con vection energy.

2. A furnace for heating hydrocarbon oil, comprising a housing, acombustion zone and source of heat therein, a plurality of seriallyconnected heating tubes disposed around said combustion zone, finsprojecting from the peripheral surfaces of said tubes in substantialoverlapped relation to form a substantially continuous walled enclosureabout said combustion zone and impart radiant heat to the partialperipheral surface portions of said tubes disposed within said zone, aconvection zone adjacent said combustion zone within which the oppositepartial peripheral surface portions of said tubes are heatedconcurrently by convection, and means to pass products of combustionfrom said combustion zone to said convection zone.

3. A process of converting hydrocarbon oil during its forced passagethrough a plurality of serially connected heating tubes, comprisingsubjecting said oil to concurrent, opposed and separate heating byradiant and convection energy by exposing a limited portion of thecircumferential area of each of said tubes to radiant heat within aradiant heating zone, simultaneously exposing the opposite and remainingcircumferential area of each tube to convection heat within a convectionheating zone, and preventing the radiant and/or convection heatedportion of each of said tubes from being subjected to convection and/orradiant heat respectively, by forming a barrier between the radiant heatzone and the convection heat zone.

4. In the heating of hydrocarbon oil to conversion temperatures whilepassing through a plurality of heating tubes disposed in a furnace, themethod which comprises burning fuel to generate flame adjacent a portionof the peripheral surface of said tubes and heating this portion of thetubes predominantly by radiation, including direct radiant heat from theflame, passing resultant combustion gases along the opposite portion ofthe peripheral surface of the tubes and heating this portion of thetubes predominantly by convection from the gases.

JOSEPH G. ALTHER.

